Ethernet over twisted-pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. They are a subset of all Ethernet physical layers.
In telecommunications and professional audio, a balanced line or balanced signal pair is an electrical circuit consisting of two conductors of the same type, both of which have equal impedances along their lengths, to ground, and to other circuits. The primary advantage of the balanced line format is good rejection of common-mode noise and interference when fed to a differential device such as a transformer or differential amplifier.
Coaxial cable, or coax, is a type of electrical cable consisting of an inner conductor surrounded by a concentric conducting shield, with the two separated by a dielectric ; many coaxial cables also have a protective outer sheath or jacket. The term coaxial refers to the inner conductor and the outer shield sharing a geometric axis.
Low-voltage differential signaling (LVDS), also known as TIA/EIA-644, is a technical standard that specifies electrical characteristics of a differential, serial signaling standard. LVDS operates at low power and can run at very high speeds using inexpensive twisted-pair copper cables. LVDS is a physical layer specification only; many data communication standards and applications use it and add a data link layer as defined in the OSI model on top of it.
Balanced audio is a method of interconnecting audio equipment using balanced interfaces. This type of connection is very important in sound recording and production because it allows the use of long cables while reducing susceptibility to external noise caused by electromagnetic interference. The balanced interface guarantees that induced noise appears as common-mode voltages at the receiver which can be rejected by a differential device.
A balun is an electrical device that allows balanced and unbalanced lines to be interfaced without disturbing the impedance arrangement of either line. A balun can take many forms and may include devices that also transform impedances but need not do so. Sometimes, in the case of transformer baluns, they use magnetic coupling but need not do so. Common-mode chokes are also used as baluns and work by eliminating, rather than rejecting, common mode signals.
RS-422, also known as TIA/EIA-422, is a technical standard originated by the Electronic Industries Alliance, first issued in 1975, that specifies electrical characteristics of a digital signaling circuit. It was meant to be the foundation of a suite of standards that would replace the older RS-232C standard with standards that offered much higher speed, better immunity from noise, and longer cable lengths. RS-422 systems can transmit data at rates as high as 10 Mbit/s, or may be sent on cables as long as 1,200 meters (3,900 ft) at lower rates. It is closely related to RS-423, which uses the same signaling systems but on a different wiring arrangement.
In electronics, electrical termination is the practice of ending a transmission line with a device that matches the characteristic impedance of the line. Termination prevents signals from reflecting off the end of the transmission line. Reflections at the ends of unterminated transmission lines cause distortion, which can produce ambiguous digital signal levels and misoperation of digital systems. Reflections in analog signal systems cause such effects as video ghosting, or power loss in radio transmitter transmission lines.
Differential TTL is a type of binary electrical signaling based on the transistor-transistor logic (TTL) concept. It enables electronic systems to be relatively immune to noise. RS-422 and RS-485 outputs can be implemented as differential TTL.
In an electrical system, a ground loop or earth loop occurs when two points of a circuit are intended to have the same ground reference potential but instead have a different potential between them. This is typically caused when enough current is flowing in the connection between the two ground points to produce a voltage drop and cause the two points to be at different potentials. Current may be produced in a ground loop by electromagnetic induction.
RS-485, also known as TIA-485(-A) or EIA-485, is a standard, originally introduced in 1983, defining the electrical characteristics of drivers and receivers for use in serial communications systems. Electrical signaling is balanced, and multipoint systems are supported. The standard is jointly published by the Telecommunications Industry Association and Electronic Industries Alliance (TIA/EIA). Digital communications networks implementing the standard can be used effectively over long distances and in electrically noisy environments. Multiple receivers may be connected to such a network in a linear, multidrop bus. These characteristics make RS-485 useful in industrial control systems and similar applications.
Single-ended signaling is the simplest and most commonly used method of transmitting electrical signals over wires. One wire carries a varying voltage that represents the signal, while the other wire is connected to a reference voltage, usually ground. The main alternative to single-ended signaling is called differential signaling where the two conductors carry signals equal in magnitude but of opposite electric polarity.
Signal integrity or SI is a set of measures of the quality of an electrical signal. In digital electronics, a stream of binary values is represented by a voltage waveform. However, digital signals are fundamentally analog in nature, and all signals are subject to effects such as noise, distortion, and loss. Over short distances and at low bit rates, a simple conductor can transmit this with sufficient fidelity. At high bit rates and over longer distances or through various mediums, various effects can degrade the electrical signal to the point where errors occur and the system or device fails. Signal integrity engineering is the task of analyzing and mitigating these effects. It is an important activity at all levels of electronics packaging and assembly, from internal connections of an integrated circuit (IC), through the package, the printed circuit board (PCB), the backplane, and inter-system connections. While there are some common themes at these various levels, there are also practical considerations, in particular the interconnect flight time versus the bit period, that cause substantial differences in the approach to signal integrity for on-chip connections versus chip-to-chip connections.
Parallel SCSI is the earliest of the interface implementations in the SCSI family. SPI is a parallel bus; there is one set of electrical connections stretching from one end of the SCSI bus to the other. A SCSI device attaches to the bus but does not interrupt it. Both ends of the bus must be terminated.
The Fibre Channel electrical interface is one of two related Fibre Channel standards that can be used to physically interconnect computer devices. The other standard is a Fibre Channel optical interface, which is not covered in this article.
Twinaxial cabling, or twinax, is a type of cable similar to coaxial cable, but with two inner conductors in a twisted pair instead of one. Due to cost efficiency it is becoming common in modern (2013) very-short-range high-speed differential signaling applications.
Various types of electrical transformer are made for different purposes. Despite their design differences, the various types employ the same basic principle as discovered in 1831 by Michael Faraday, and share several key functional parts.
In electrical engineering, a balanced circuit is electronic circuitry for use with a balanced line, or the balanced line itself. Balanced lines are a common method of transmitting many types of electrical signals between two points on two wires. In a balanced line, the two signal lines are of a matched impedance to help ensure that interference, induced in the line, is common-mode and can be removed at the receiving end by circuitry with good common-mode rejection. To maintain the balance, circuit blocks which interface to the line or are connected in the line must also be balanced.
In electrical engineering, a common-mode signal is the identical component of voltage present at both input terminals of an electrical device. In telecommunication, the common-mode signal on a transmission line is also known as longitudinal voltage.
In electrical engineering, star-quad cable is a four-conductor electrical cable that has a special quadrupole geometry which provides magnetic immunity when used in a balanced line. Four conductors are used to carry the two legs of the balanced line. All four conductors must be an equal distance from a common point. The four conductors are arranged in a four-pointed star. Opposite points of the star are connected together at each end of the cable to form each leg of the balanced circuit.
